This invention relates to improvements in electronic sound or image reproduction apparatus.
The quality of sound reproduction from electronic apparatus has greatly improved in recent times due in part to the advances in electronic technology and due to the use of multi-channel carrier signals or multiplexed broadcast signals which may be encoded for transmission and decoded by a receiver to provide a plurality of discrete signals for amplification and reproduction by separate speaker assemblies. The benefits of these systems are well known. The reproduction of music for example from such stereo systems more closely approaches the original sound particularly where the respective speaker assemblies can be widely separated to provide the appropriate stereo imagery.
To date remote speaker assemblies have been physically connected by cables to the amplifier and while this may not be a major disadvantage in fixed installations, it is sometimes difficult to conceal the interconnecting cable so that installation is untidy. Also to date such assemblies have included two separable speakers connected by extension leads to a central receiver/player. Such arrangements are cumbersome and expensive to produce. In addition, the placement of the cables may be hazardous. In portable installations the provision of wires interconnecting the amplifier and the speaker assemblies is cumbersome as the connection leads must be carried with the apparatus and of course the separation of the speaker assemblies is limited by the length of the connection leads. This inconvenience will generally preclude arrangement of the system to produce a stereophonic sound field in outdoor locations. The attaching cords will also preclude temporary relocation of the transmitter assembly or control unit to provide at hand convenience of control for the operator. Audio systems to data incorporating remote controls either corded or cordless are expensive and rely on the transmission of controlling signals to the receiver/player unit. Accordingly, as the receiver/player itself is not portable, operations including changing a recorded signal source such as turning over or replacing a record or cassette, are not possible, from the remote control. A further disadvantage associated with conventional portable receiver/player amplification apparatus whether they provide stereo or mono reproduction, is that for economy and convenience the speaker assemblies are often integral with the receiver/player assembly so that in use the speaker assembly is usually located adjacent an operator in order that the operator may control the output thereof. Similar disadvantages occur in other conventional audio and audio visual apparatus.